Sewing machine



March 27, 1945.

v N. v. CHRISTENSEN SEWING MACHINE Filed Nov. 18, 1942 5 Sheets-Sheet 1 ATTORN Y.

March 27, 1945..

N; V. CHRISTENSEN SEWING MACHINE Filed Nov. 18, 1942 5 Sheets-$ha9t 2 INVENTOR. Wow/4 d'w/srf/mm/ 1945. N. v. CHRISTENSEN SEWING MACHINE March 27 Fiied Nov. 18', 1942 5 Sheets-Sheet 3 v INVENTOR. mun/v lffiw/srz/vasm ATTORNEY.

March 27, 19 45.

N. v. CHRISTENSEN 2,372,175

SEWING MACHINE Filed Nov. 18, 1942 5 Sheets-Sheet, 4

QNN

Patented Mar. 27, 1945 UNITED STAT ES OFFICE.

2,372,175 SEWING MACHINE.

Norman V. Christensen, ,ChicagmIlL, assigns: to

Union Special Machine company, Chicago, 111;,

acorporation of Illinois i Application November 18, leaaj'senai No. 455,947

4 Claims. (o lie- 256) This invention relates to a sewing machine and associated devices and more particularly to the provision of improved devices in a sewing machine and in combination therewith for insuring proper lubrication of all of the important .bearing surfaces in'the machine.

An object of the invention has been to provide a simple and inexpensive construction which will insure the maintenance of anadequate supply of lubricant in a reservoir at a. sufficiently high point within the frame of the machine to enable delivery of the lubricant automatically, through the aid of gravity, to all of the parts requiring lubrication. Toward this end provision is made for the lifting of the lubricant, from a main reservoir or sump at a relatively low point in the frame to a distributing reservoir near the top of the frame, as an incident to the initiation of the operation of the machine. The means employed for this purpose is so constructed that with substantially no effort and with no special attention by the operator it serves to transfer periodicallyadesired amount of lubricant to the distributing reservoir. At the same time objections inherent in force feed lubrication systems, in which oilis' delivered to Various bearings under pressure by the constant operation of a pump, are eliminated.- The arrangement is such, moreover, that any ex cess lubricant delivered to the various" bearing surfaces .will be returned to the main sump or reservoir at the bottom of theframe of themechine and will be available for recirculation.

A special feature of the invention is the provision of visual means for disclosing to the operator at all times whether or not the lubrication system is functioning properly and also the condition of the lubricant being utilized. If the lubricant becomes dirty, dueto excessive use, or loses its" desired body, its condition may be readily noted by the operator and care taken to clean out the lubricating system and introduce a fresh supply of oil. The same means may serve, in a measure, to indicate whether an adequate quantity of lubricant is available for circulation in the system.

However, a special gauge is preferably provided" to combination embodying one form of the inven tion.

Fig. II is a front elevation of the sewing ma-' chine, certain cover plates being removed and portions being broken away and shown in section for purposes of better illustration.

' Fig..III is a rear elevation of the machine with certain parts broken away for clearness of illustration.

Fig. IV is a top plan view of the machine with portions brokenaway and certain cover plates removed to better illustrate the construction.

Fig. V is a plan view of a pump and associated devices employed in the lubricant circulating system, portions of the pump being broken away and shown in section.

Fig. V1 is a detail view, in section along the line ,VI- -VI of Fig. I-V,,disclosi ng a portion of the feed mechanism and the looper construction of the illustrative: machine.

Fig. VII is a detail view, in end elevation, of a portion of the: work supporting arm, and Fig. VIII is a detail view in side elevation, of the needle lever and associated parts.

For purposes of illustration, the invention has been shown applied toa feed-ofi-the-arm machine ofthe type disclosed in the Christensenet-al. Patent No. .1,74l,095. Reference may be had tosaid prior patent for a fuller disclosure of certain details of construction and operation of the machine andreferencemay also be had, for this purpose, to other patents and pending applications to be hereinafter specified. In general, the construction includes a table It) (Fig. I) arranged to'support the sewing machine II which comprises a frame having 'a main base portion I2, supported by the top of the table Ill, this base portion extending upwardly along sweepingly curved lines and terminating at its upper end in a'longitudinally extending portion l3. From one end-of the portion [3 a needle head 14 (Fig. IV) extends laterally. At the opposite end of the portion I3 there is provided a depending hollow portion [5 (Figs. II and III) having connected thereto, at its lower end, a work supporting arm l6- which extends outwardly from portion 15 to a point beneath the needle head t4. Mounted in suitable bearings I l (Fig-.IV) l8, l9, and 20 (Fig. II) ,within the portion I-3 of the frame, is a main drive shaft 2| which extends beyond the frame at one end and. has secured thereto, outside of the frame, a combined hand wheel and pulley 22. The latter (Fig.1) is connected by a belt 23 with a pulley 24 forming. part of a driving unit supported beneath the top of the table I'll. This supporting arm It.

effected at will by the operator of the machine in any suitable way, as by means of a treadle 21 on the floor beneath the sewing machine. This treadle may be connected by a link 28 with an arm 29 secured to a rock shaft 30 suitably journaled in bearings carried by the supporting legs for the table Ill. 30 has secured thereto an arm 3| connected by a rod or link 32 with the clutch operating lever 26. A spring 32a is interposed in the connection between the rod 32 and the lever 26 to provide a yielding action on the latter and a certain amount of play.

Referring now to Figs. 11 and IV, the shaft 2| is provided between the bearings H and I8 with a crank 33, the latter being connected by a pitman 34 with a downwardly extending arm 35 of a needle lever having a trunnion 36 which is journaled in bearings 31 and 38 carried by the needle head. A forwardly extending arm 39 of the needle lever is connected by a link 49 with a block ll secured to a vertically reciprocable needle bar 42. At the lower end of the needle bar there is mounted one or more needles 43 which are reciprocated with the bar in the formation of stitches. For further details as to the construction and operation of the foregoing mechanism, reference may be had to the application of Clarence C. Smith, Ser. No. 425,497, filed January 3, 1942. At the end of the shaft 2| within the hollow vertical portion l of the frame a-ball crank 53 is provided, this being connected through linkage :14 with a crank arm 45 secured to a shaft 46 mounted in suitable bearings within the work As more fully disclosed in said pending Smith application, the shaft 46 carries at its opposite end a series of loopers 4'! (Fig. VI) which are oscillated in synchronism with the reciprocation of the needles to form the desired stitches.

An eccentric also carried by the shaft 2|, adjacent the bearing sleeve 20, cooperates with a strap it carried at the upper end of a pitman 49 whose lower end is connected with a suitable device (not shown) for imparting the feed stroke to the feed dog 59 (Fig. VI) and to impart the needle-avoid movements to the loopers 41. Suitable mechanism for this purpose is disclosed in the patent to Kucera, No. 2,199,666, granted May '1, 1940. Another eccentric secured to the shaft 2i, cooperating with a strap 5| carried at the upper end of a pitman 52, serves to impart the desired lifting movements to the feed dog 59. The connections for this purpose are not shown but may suitably be of the type disclosed in the above-mentioned patent to Kucera.

In the lowermost portion of the work supporting arm l5, directly below the hollow, depending portion I5 of the frame, there is provided a sump or lubricant reservoir 53 (Fig. III) into Which extends the lower end of an oil intake tube or suction pipe 54. A suitable filteror screen 55 may be provided around the intake end of the pipe 54, if desired. This pipe extends upwardly through the interior of the depending portion I5 Intermediate its ends the shaft of the frame and at the top of the latter is bent laterally just beneath a cover 55 which closes a part of the longitudinally extending portion l3 ence character 59.. Within the chamber 58 is a spring pressed ball check-valve 69 (Fig. V). The interior of the chamber is connected by a passage t I, within a tubular extension 62 of the pump unit, with an intake port 63 of a cylinder 64 forming part of a reciprocating pump. At the opposite end of the tubular member 62 is provided a second valve chamber 65 having therein a second ball check-valve 63. Chamber 65 is connected by a nipple 61 with a conduit 68 which serves to deliver the lubricant to the interior of a transparent dome 69 (Fig. II) forming part of a closure for a reservoir 19. The latter is secured by screws Illa (Fig. IV) to the underside of a cover member 1| at the top of the longitudinally extending portion I3 of the frame. Dome 69, which may suitably be formed of glass or some transparent, plastic material, may be conveniently mounted in the cover member H for removal and application therewith. In fact, the entire reservoir 10 with its associated conduits may, if desired, be adapted for assembly and removal as a unit with the cover member 1|.

Within the cylinder 64 there is mounted, for reciprocation, a piston 72 at the end of a piston rod '13. A spring 14 coiled about the piston rod within the cylinder normally serves to urge the piston toward the right (Fig. V). The outer end of the piston rod carries a T-shaped cap member 15 adapted to receive the bent-over end of an operating rod 75. The latter may be held in place in any suitable manner, as by means of a cotter pin '11. At its opposite end the rod 16 is booked and engaged with a depending arm of a bell crank lever 78 (Fig. III) pivoted at 79 upon a block 89 (Fig. IV) secured to a portion of the frame. The other arm of the bell crank 78 is connected by any suitable means, such as a flexible chain 8|, with the arm 29 (Fig. I), hereinbefore mentioned, secured to the shaft 39. The arrangement is such that upon each operation of the treadle 2! to initiate an operation of the sewing machine, the bell crank 19 will be rocked in a clockwise direction (Fig. III) and will urge the piston 12 toward the left (Figs. III and V).

This will cause oil to be drawn into the cylinder 64 past the ball check-valve 69, the oil so drawn being delivered from the sump 53 by means of the tubing 54. As the pressure on the treadle is released, or when the latter is rocked in the opposite direction to throw out the clutch and stop the sewing machine, the spring 74 will urge the piston 72 toward the right. This will force the oil from the cylinder through the check valve 66 into the tubing 58 and will deliver the oil against the inner surface of the dome 69. As indicated in Fig. III, the pump unit 59 may be secured to the sloping surface of the upper portion of the frame of the machine by means of screws 82.

From the reservoir It the oil is delivered to the various bearing surfaces to be lubricated. A wick 83 (Fig. II) extending into the reservoir is passed outwardly therefrom through a tube 84 which terminates in an opening 85 (Fig. IV) extending into the interior of the bearing bushing H. The

, interior of the bearing sleeve I9.

oil so delivered by the wick 83 serves to lubricate. the outer bearing of the main drive shaft. IAn. oil slinging shoulder or rib 86 formed on a hub extension of the pulley 22 serves to. prevent the escape of lubricant at the outer end of the bearins.

A other wick 88 (Fig. II) dipping into the oil in the reservoir 10 and passing outwardly from said reservoir through a tube 89 terminates withma. pocket 90 packed with felt or other suitable absorbent material 9|. Ihe bottom of the pocket 9II communicates with an opening 92 through the. bearing sleeve I8 and thus serves to deliver lubricant to this bearing. Any excess lubricant so delivered, working its way toward the right in Fig. II, will be delivered to a recess 93 in the. frame between the bearings I8 and I9. A wickfil-led tube 94 communicating at its upper endv with the upper portion of the pocket 90 and at its lower endwith a groove 95 in the; end of the bearing sleeve I8 serves to deliver some of the lubricant to this point, from which it is passed to a small, annular recess 95 in the face of the needle lever operating crank. This portion of the lubricant will then be delivered through a channel 91 (Fig. IV) extending longitudinally of the crank element 33 and will be discharged radially from this channel through a passage 98 to the outer surface of the crank element. Here it will serve to lubricate the roller bearing elements cooperating with the crank and a. portion of the lubricant will. pass on through a channel 99, extending longitudinally of the pitman, to the pivot pin connecting the latter with the needle lever.

A tube I03 extending outwardly from the. opposite side of the reservoir ID at a point near its top serves to deliver some of the lubricant to a pocket I04 filled with suitable packing I05 and communicating through an opening I06 with the Tube I03 serves not only to supply lubricant to the bearing IS in this manner but also serves as an over flow for the excess lubricant delivered to the reservoir I0. Its inlet end is preferably slightly lower than the inner ends of the wick carrying tubes above described. Any excess oil discharged through the tube I03 will work through the bearing I9 into the recess 93, to be delivered from the latter through a channel IOI'to the interior of the hollow depending portion I5 of the frame, or it will be delivered directly into this hollow portion from the opposite end of the sleeve I3. Eventually, all of such excess oil will be returned to the sump 53. A plurality of wicks I08 dipping into the oil in the reservoir III are passed outwardly from the latter through a relatively large tube I03 having a series of discharge branches I I0, III, H2 and I I3 through which the separate wicks extend to points adjacent the members to be lubricated. Branch III) delivers lubricant to the eccentric cooperating with strap 5|; branch II delivers lubricant to the strap 48, while branch II'2 delivers lubricant to a pocket I I4 filled with packing H5 and communicating through passage IIIi with the interior of the bearing sleeve 25. Branch I I3 serves to deliver lubricant to the'ball crank 43. Any excess lubricant delivered by th wick I08 to the various parts mentioned, within or above the depending hollow portion I5 of the frame, willdescend along the various pitmans orlinks, or will drop directly, into the body of oil in the sump. If desired, a special gasket II'I may be provided between the portion I5 of the-frame and the work supporting arm portion I6 of the frame,

this gasket being of the type disclosed. in the pat out to Rubel et al., No. 1,812,377 granted June 30, 1931; The gasket may be formed of any suitable material, such as copper or an appropriate plas-.

tic and may be so formed as to collect the excess lubricant returning to the sump and direct it against bearing surfaces within the work. arm before it is delivered to the sump.

An oil'inlet IIB (Figs. II and IV) may be provided in the cover member =II for the introduction of lubricant directly into the reservoir III whenever required. This oil will eventually reach the sump through the channels above indicated. Oil may, if desired, be introduced directly into the sump through an opening. in the wall of. the work supporting arm normally closed by a plug or a plate I IBa. If the oil is introduced directly into thesump it will be desirable to operate the tree-- dle '21 a number of times at the commencement of an operation, before starting the motor, in

- order to transfer oil to the reservoir. This may be desirable in any event after a long idle period. For the purpose of disclosing the amount of lubricant available at all times in the sump 53, the end wall ofthe. work supporting arm I5 may beprovided with a removable plate I I9 secured in a recess in said end wall by a plurality of screws I20 (Fig. VII). The plate may be provided with a transparent. gauge element I 2 I formed of glass or a, suitable plastic, preferably having a series of transverse grooves I22 on its inner face which is in'contact with the oil. These grooves are preferably filled with some appropriate coloring matter to increase their visibility. They may be so disposed, for example, as to indicate the upper and lower limits, and the half-way mark, of the body of oil to be maintained in the reservoir.

Any suitable arrangement may be provided for tensioning and controlling the needle and looper threads. These devices are not disclosed herein in detail since their construction and operation are well known. However, itshould be observed that a thread controller I23 (Fig. II) for the looper threads is mounted directly upon the main operating shaft 2| and the improved lubrication system, described in the foregoing, is such that danger of soiling, by depositing oil upon, the looper threads in, their passage to and from, as well as around, the thread controller is avoided. The looper threads are delivered from thread tensioning devices I24 (Figs. II and IV) and pass into the interior of the frame through a slot I25 in the wall of the portion I3 of the frame. After cooperation with the thread controller, the threads are passed outwardly through a slot I26, (Fig. IV) at the opposite side of the portion I3 of the frame, and thence through suitable apertures in a guide I21 from which they pass to other guides and thence to the loopers, in a manner well known in the art. The thread controller may suitably be of the type disclosed in the patent to Christensen et al., No. 1,864,407, granted June 21, 1932, while the thread tensionin devices may be of-the type disclosed in the patent to Berger et a1., No. 1,758,349, granted May- 13, 1930.

. The operation of the improved lubrication system is believed to be apparent from 'theforegoing. To initiate an operationofthe machine for the formation of stitches, the treadle 21 will be rocked to cause counter-clockwise rotation of the shaft 35 and arm 3| (Fig. I), thereby engaging the clutch of the driving unit. Atthe same time the flexible connection 8-I- from the arm- 23 to the bell crank 18 serves to shift the piston I2 toward the left (Figs. III and V) and thereby draws oil from the sump 53 through the tubing 54 into the cylinder 64. At the end of the stitching operation, the treadle 21 is restored to its original position and the spring 14 within the pump cylinder will restore the piston 12 toward the right and will force the oil through the tubing 68. In this way somewhat more oil than is required for the proper lubrication of all of the bearing surfaces of the machine, during a normal stitching operation, will be transferred from the sump to the reservoir Ill upon the formation of each seam. The lubricant so delivered to the reservoir is distributed through the combined operation of gravity and capillary action to the principal bearing surfaceswithin the machine. The wick-filled tubes forming a part of the oil delivery system constitute, in effect, capillary syphons. They first lift the oil slightly from within the reservoir 10 and then deliver it at lower points at the outer ends of the tubes.

While an illustrative form of the invention has been disclosed in considerable detail in the foregoing, it will be understood that the invention is capable of broader application and numerous changes may be made in the construction and arrangement of the various parts.

What I claim is:

1. A sewing machine having a frame comprising a main longitudinally extending portion, a hollow depending portion at one end of said main portion and a work supportingarm projecting from the lower end of said depending portion, an oil sump in said arm, a reservoir in said main portion of said frame, a drive shaft journaled in bearings in said main portion, a reciprocating pump mounted at a readily accessible point on the outer surface of said frame for transferring oil from said sump to saidreservoir, means for delivering oil from said reservoir to the bearings for said shaft, power means for driving said shaft, and a treadle for operating said pump and simultaneously controlling the operation of said shaft by said driving means, the connection between said treadle and said pump being positive, and the connection from said treadle for controlling the operation of said shaft being yielding and involving play.

2. A sewing machine having a frame comprising a main longitudinally extending portion, a hollow depending portion at one end of said main portion and a work supporting arm projectingfrom the lower end of said depending portion, an oil sump in said arm, means for indicating at all times the quantity of oil in said sump, a reser-,

voir in said main portion of said frame, a drive shaft journaled in bearings in said main portion, a pump for transferring oil from said sump to said reservoir, means associated with said reservoir for indicating the condition of the oil transferred thereto, means for delivering oil from said reservoir to the bearings for said shaft, power means for driving said shaft, and means operable at will for operating said pump and simultaneously controlling the operation of said shaft by said driving means, the connection between said means operable at will and said pump being positive, and the connection from said means operable at will for controlling the operation of said shaft being yielding and involving play.

3. A sewing machine comprising a frame having an upper horizontally extending portion with a needle head disposed at one end thereof and having a fixed work supporting member extending beneath said needle head, stitch forming and work feeding devices carried by said needle head and work supporting member, driving means in said frame for operating said stitch forming and main reservoir for lubricant in a low portion of the frame, a chamber forming a distributing reservoir adjacent the top of said frame, conduits leading from said distributing reservoir for delivering oil therefrom to said relatively sliding surfaces of said driving means, a pump for transferring oil from said sump to said distributing reservoir, means operable at will upon movement of the leg of the operator for controlling both the connection and disconnection of said power means and said driving means, and connections from said means operable at will to said pump for operating the latter only once upon each operation of said means, the connection from said means operable at will to said pump being positive and the connection therefrom for controlling the connection and disconnection of said powerimeans and driving means being yielding and involving play.

4. A sewing machine comprising a frame having an upper horizontally extending portion with a needle head disposed at one end thereof and having a fixed work supporting member extending beneath said needle head, stitch forming and work feeding devices carried by said needle head and work supporting member, driving means in saidframe for operating said stitch forming and work feeding devices, said driving means having surfaces which slide relative to each other repeatedly a widely variable number of times during each operation of the machine, an electric motor, means including a clutch for connecting said motor with said driving means, clutch controlling means operable at will upon movement of the leg of the operator for both engaging and disengaging said clutch, said frame being formed to provide a completely enclosed lubrication system including an oil sump arranged to receive excess lubricant from points lubricated and forming a main reservoir for lubricant in a low portion Oftheframe, a chamber disposed within said horizontally extending portion of the frame forming a distributing reservoir adjacent the top of said frame, conduits leading from said distributing reservoir for delivering oil therefrom to said relatively sliding surfaces of said driving means, a pump for transferring oil from said sump to said distributing reservoir, an overfiow pipe arranged to return excess oil from a relatively high level within said distributing reservoir to said sump, and connections from said clutch controlling means to said pump for operating the latter a predetermined extent only once upon each operation of said means, said connections for operating the pump being independent of said motor and the connections therefrom to said driving means.

NORMAN V. CHRISTENSEN. 

